Feasibility of a telehealth-based contingency management intervention for alcohol use disorders using the phosphatidylethanol (PEth) 16:0/18:1 alcohol biomarker: a pilot randomized trial

Background: Phosphatidylethanol (PEth) is a blood-based biomarker for alcohol consumption that can be self-collected and has high sensitivity, specificity, and a longer detection window compared to other alcohol biomarkers.Objectives: We evaluated the feasibility and acceptability of a telehealth-based contingency management (CM) intervention for alcohol use disorder (AUD) using the blood-based biomarker PEth to assess alcohol consumption.Methods: Sixteen adults (7 female, 9 male) with AUD were randomized to Control or CM conditions. Control participants received reinforcers regardless of their PEth levels. CM participants received reinforcers for week-to-week decreases in PEth (Phase 1) or maintenance of PEth consistent with abstinence (<20 ng/mL, Phase 2). Blood samples were self-collected using the TASSO-M20 device. Acceptability was assessed by retention in weeks. Satisfaction was assessed with the Client Satisfaction Questionnaire (CSQ-8) and qualitative interviews. The primary efficacy outcome was PEth-defined abstinence. Secondary outcomes included the proportion of visits with PEth-defined heavy alcohol consumption, negative urine ethyl glucuronide results, and self-reported alcohol use.Results: Retention averaged 18.6 ± 8.8 weeks for CM participants. CM participants reported high levels of satisfaction (CSQ-8, Mean = 30.3 ± 1.5). Interview themes included intervention positives, such as staff support, quality of life improvement, and accountability. 72% of PEth samples from CM participants were consistent with abstinence versus 34% for Control participants (OR = 5.0, p = 0.007). PEth-defined heavy alcohol consumption was detected in 28% of CM samples and 52% of Control samples (OR = 0.36, p = 0.159). CM participants averaged 1.9 ± 1.7 drinks/day versus 4.2 ± 6.3 for Control participants (p = 0.304).Conclusion: Results support the acceptability and satisfaction of a telehealth PEth-based CM intervention, though a larger study is needed to assess its efficacy [NCT04038021].

Cardiovascular and Locomotor Effects of Binary Mixtures of Common "Bath Salts" Constituents: Studies with Methylone, MDPV, and Caffeine in Rats

Background and Purpose

The use of "Bath Salts" drug preparations has been associated with high rates of toxicity and death. Preparations often contain mixtures of drugs including multiple synthetic cathinones or synthetic cathinones and caffeine; however, little is known about whether interactions among "Bath Salts" constituents contribute to the adverse effects often reported in users.

Experimental Approach

This study used adult male Sprague-Dawley rats to characterize the cardiovascular effects, locomotor effects, and pharmacokinetics of methylone, MDPV, and caffeine, administered alone and as binary mixtures. Dose-addition analyses were used to determine the effect levels predicted for a strictly additive interaction for each dose pair.

Key Results

Methylone, MDPV, and caffeine increased heart rate and locomotion, with methylone producing the largest increase in heart rate, MDPV producing the largest increase in locomotor activity, and caffeine being the least effective in stimulating heart rate and locomotor activity. MDPV and caffeine increased mean arterial pressure, with caffeine being more effective than MDPV. The nature of the interactions between methylone and MDPV tended toward sub-additivity for all endpoints, whereas interactions between MDPV or methylone and caffeine tended to be additive or sub-additive for cardiovascular endpoints, and additive or supra-additive for increases in locomotion. No pharmacokinetic interactions were observed between individual constituents, but methylone displayed non-linear pharmacokinetics at the largest dose evaluated.

Conclusion and Implications

These findings demonstrate that the composition of "Bath Salts" preparations can impact both cardiovascular and locomotor effects and suggest that such interactions among constituent drugs could contribute to the "Bath Salts" toxidrome reported by human users.

Astaxanthin and meclizine extend lifespan in UM-HET3 male mice; fisetin, SG1002 (hydrogen sulfide donor), dimethyl fumarate, mycophenolic acid, and 4-phenylbutyrate do not significantly affect lifespan in either sex at the doses and schedules used

In genetically heterogeneous (UM-HET3) mice produced by the CByB6F1 × C3D2F1 cross, the Nrf2 activator astaxanthin (Asta) extended the median male lifespan by 12% (p = 0.003, log-rank test), while meclizine (Mec), an mTORC1 inhibitor, extended the male lifespan by 8% (p = 0.03). Asta was fed at 1840 ± 520 (9) ppm and Mec at 544 ± 48 (9) ppm, stated as mean ± SE (n) of independent diet preparations. Both were started at 12 months of age. The 90th percentile lifespan for both treatments was extended in absolute value by 6% in males, but neither was significant by the Wang-Allison test. Five other new agents were also tested as follows: fisetin, SG1002 (hydrogen sulfide donor), dimethyl fumarate, mycophenolic acid, and 4-phenylbutyrate. None of these increased lifespan significantly at the dose and method of administration tested in either sex. Amounts of dimethyl fumarate in the diet averaged 35% of the target dose, which may explain the absence of lifespan effects. Body weight was not significantly affected in males by any of the test agents. Late life weights were lower in females fed Asta and Mec, but lifespan was not significantly affected in these females. The male-specific lifespan benefits from Asta and Mec may provide insights into sex-specific aspects of aging.

Validation of the quantification of phosphatidylethanol 16:0/18:1 concentrations in TASSO-M20 devices

BACKGROUND

Phosphatidylethanol 16:0/18:1 (PEth), found in whole blood, is a biomarker for alcohol consumption with high sensitivity, specificity, and a long detection window. The TASSO-M20 device is used to self-collect capillary blood from the upper arm and has advantages over finger stick methods. The purpose of this study was to (1) validate PEth measurement using the TASSO-M20 device, (2) describe the TASSO-M20 for blood self-collection during a virtual intervention, and (3) characterize PEth, urinary ethyl glucuronide (uEtG) and self-reported alcohol in a single participant over time.

METHODS

PEth levels in blood samples dried on TASSO-M20 plugs were compared to those in (1) liquid whole blood (N = 14) and (2) dried blood spot cards (DBS; N = 23). Additionally, the self-reported drinking, positive or negative uEtG results (dip card cutoff ≥300 ng/mL), and observed self-collection of blood with TASSO-M20 devices for PEth levels were obtained over time during virtual interviews of a single contingency management participant. High-performance liquid chromatography with tandem mass spectrometry detection was used to measure PEth levels for both preparations.

RESULTS

PEth concentrations from dried blood on TASSO-M20 plugs and liquid whole blood were correlated (0 to 1700 ng/mL; N = 14; r2  = 0.988; slope = 0.951) and in a subgroup of samples with lower concentrations (N = 7; 0 to 200 ng/mL; r2  = 0.944, slope = 0.816). PEth concentrations from dried blood on TASSO-M20 plugs and DBS were correlated (0 to 2200 ng/mL; N = 23; r2  = 0.927; slope = 0.667) and in a subgroup of samples with lower concentrations (N = 16; 0 to 180 ng/mL; r2  = 0.978, slope = 0.749). Results of the contingency management participant indicate that changes in PEth levels (TASSO-M20) and uEtG concentrations were consistent with each other and with changes in self-reported alcohol use.

CONCLUSIONS

Our data support the utility, accuracy, and feasibility of using the TASSO-M20 device for blood self-collection during a virtual study. The TASSO-M20 device had multiple advantages over the typical finger stick method, including consistent blood collection, participant acceptability, and less discomfort as indicated by acceptability interviews.

Massed vs Intensive Outpatient Prolonged Exposure for Combat-Related Posttraumatic Stress Disorder: A Randomized Clinical Trial

IMPORTANCE

Improved, efficient, and acceptable treatments are needed for combat-related posttraumatic stress disorder (PTSD).

OBJECTIVE

To determine the efficacy of 2 compressed prolonged exposure (PE) therapy outpatient treatments for combat-related PTSD.

DESIGN, SETTING, AND PARTICIPANTS

This randomized clinical trial was conducted among military personnel and veterans at 4 sites in Texas from 2017 to 2019. Assessors were blinded to conditions. Data were analyzed from November 2020 to October 2022.

INTERVENTIONS

The interventions were massed-PE, which included 15 therapy sessions of 90 minutes each over 3 weeks, vs intensive outpatient program PE (IOP-PE), which included 15 full-day therapy sessions over 3 weeks with 8 treatment augmentations. The IOP-PE intervention was hypothesized to be superior to massed-PE.

MAIN OUTCOMES AND MEASURES

Coprimary outcomes included the Clinician-Administered PTSD Scale for Diagnostic and Statistical Manual of Mental Disorders (Fifth Edition) (DSM-5) (CAPS-5) and the PTSD Checklist for DSM-5 (PCL-5) administered at baseline and posttreatment follow-ups. Measures ranged from 0 to 80, with higher scores indicating greater severity. Diagnostic remission and reliable change were secondary outcomes.

RESULTS

Among 319 military personnel and veterans screened, 234 were randomized (mean [SD] age, 39.20 [7.72] years; 182 [78%] male participants), with 117 participants randomized to IOP-PE and 117 participants randomized to massed-PE. A total of 61 participants (26%) were African American, 58 participants (25%) were Hispanic, and 102 participants (44%) were White; 151 participants (65%) were married. Linear mixed-effects models found that CAPS-5 scores decreased in both treatment groups at the 1-month follow-up (IOP-PE: mean difference, -13.85 [95% CI, -16.47 to -11.23]; P < .001; massed-PE: mean difference, -14.13 [95% CI, -16.63 to -11.62]; P < .001). CAPS-5 change scores differed from 1- to 6-month follow-ups (mean difference, 4.44 [95% CI, 0.89 to 8.01]; P = .02). PTSD symptoms increased in massed-PE participants during follow-up (mean difference, 3.21 [95% CI, 0.65 to 5.77]; P = .01), whereas IOP-PE participants maintained treatment gains (mean difference, 1.23 [95% CI, -3.72 to 1.27]; P = .33). PCL-5 scores decreased in both groups from baseline to 1-month follow-up (IOP-PE: mean difference, -21.81 [95% CI, -25.57 to -18.04]; P < .001; massed-PE: mean difference, -19.96 [95% CI, -23.56 to -16.35]; P < .001) and were maintained at 6 months (IOP-PE: mean change, -0.21 [95% CI, -3.47 to 3.06]; P = .90; massed-PE: mean change, 3.02 [95% CI, -0.36 to 6.40]; P = .08). Both groups had notable PTSD diagnostic remission at posttreatment (IOP-PE: 48% [95% CI, 36% to 61%] of participants; massed-PE: 62% [95% CI, 51% to 73%] of participants), which was maintained at 6 months (IOP-PE: 53% [95% CI, 40% to 66%] of participants; massed-PE: 52% [95% CI, 38% to 66%] of participants). Most participants demonstrated reliable change on the CAPS-5 (61% [95% CI, 52% to 69%] of participants) and the PCL-5 (74% [95% CI, 66% to 81%] of participants) at the 1-month follow-up.

CONCLUSIONS AND RELEVANCE

These findings suggest that PE can be adapted into compressed treatment formats that effectively reduce PTSD symptoms.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03529435.

Lifespan benefits for the combination of rapamycin plus acarbose and for captopril in genetically heterogeneous mice

Mice bred in 2017 and entered into the C2017 cohort were tested for possible lifespan benefits of (R/S)-1,3-butanediol (BD), captopril (Capt), leucine (Leu), the Nrf2-activating botanical mixture PB125, sulindac, syringaresinol, or the combination of rapamycin and acarbose started at 9 or 16 months of age (RaAc9, RaAc16). In male mice, the combination of Rapa and Aca started at 9 months and led to a longer lifespan than in either of the two prior cohorts of mice treated with Rapa only, suggesting that this drug combination was more potent than either of its components used alone. In females, lifespan in mice receiving both drugs was neither higher nor lower than that seen previously in Rapa only, perhaps reflecting the limited survival benefits seen in prior cohorts of females receiving Aca alone. Capt led to a significant, though small (4% or 5%), increase in female lifespan. Capt also showed some possible benefits in male mice, but the interpretation was complicated by the unusually low survival of controls at one of the three test sites. BD seemed to produce a small (2%) increase in females, but only if the analysis included data from the site with unusually short-lived controls. None of the other 4 tested agents led to any lifespan benefit. The C2017 ITP dataset shows that combinations of anti-aging drugs may have effects that surpass the benefits produced by either drug used alone, and that additional studies of captopril, over a wider range of doses, are likely to be rewarding.

Phytochemical compound PB125 attenuates skeletal muscle mitochondrial dysfunction and impaired proteostasis in a model of musculoskeletal decline

Impaired mitochondrial function and disrupted proteostasis contribute to musculoskeletal dysfunction. However, few interventions simultaneously target these two drivers to prevent musculoskeletal decline. Nuclear factor erythroid 2-related factor 2 (Nrf2) activates a transcriptional programme promoting cytoprotection, metabolism, and proteostasis. We hypothesized daily treatment with a purported Nrf2 activator, PB125, in Hartley guinea pigs, a model of musculoskeletal decline, would attenuate the progression of skeletal muscle mitochondrial dysfunction and impaired proteostasis and preserve musculoskeletal function. We treated 2- and 5-month-old male and female Hartley guinea pigs for 3 and 10 months, respectively, with the phytochemical compound PB125. Longitudinal assessments of voluntary mobility were measured using Any-Maze^TM open-field enclosure monitoring. Cumulative skeletal muscle protein synthesis rates were measured using deuterium oxide over the final 30 days of treatment. Mitochondrial oxygen consumption in soleus muscles was measured using high resolution respirometry. In both sexes, PB125 (1) increased electron transfer system capacity; (2) attenuated the disease/age-related decline in coupled and uncoupled mitochondrial respiration; and (3) attenuated declines in protein synthesis in the myofibrillar, mitochondrial and cytosolic subfractions of the soleus. These effects were not associated with statistically significant prolonged maintenance of voluntary mobility in guinea pigs. Collectively, treatment with PB125 contributed to maintenance of skeletal muscle mitochondrial respiration and proteostasis in a pre-clinical model of musculoskeletal decline. Further investigation is necessary to determine if these documented effects of PB125 are also accompanied by slowed progression of other aspects of musculoskeletal dysfunction. KEY POINTS: Aside from exercise, there are no effective interventions for musculoskeletal decline, which begins in the fifth decade of life and contributes to disability and cardiometabolic diseases. Targeting both mitochondrial dysfunction and impaired protein homeostasis (proteostasis), which contribute to the age and disease process, may mitigate the progressive decline in overall musculoskeletal function (e.g. gait, strength). A potential intervention to target disease drivers is to stimulate nuclear factor erythroid 2-related factor 2 (Nrf2) activation, which leads to the transcription of genes responsible for redox homeostasis, proteome maintenance and mitochondrial energetics. Here, we tested a purported phytochemical Nrf2 activator, PB125, to improve mitochondrial function and proteostasis in male and female Hartley guinea pigs, which are a model for musculoskeletal ageing. PB125 improved mitochondrial respiration and attenuated disease- and age-related declines in skeletal muscle protein synthesis, a component of proteostasis, in both male and female Hartley guinea pigs.

Preclinical assessment of the abuse potential of purified botanical cannabidiol: self-administration, drug discrimination, and physical dependence

Cannabidiol (CBD) is a constituent of the cannabis plant with a diverse array of pharmacological activities as well as potential therapeutic uses. An oral formulation of CBD (Epidiolex^® in the US; Epidyolex^® in Europe) is approved for treating seizures associated with rare and severe forms of epilepsy. These studies, which supported the approval of the medication, investigated abuse-related effects of CBD in rats and nonhuman primates (NHPs) using drug self-administration, drug discrimination, and physical dependence procedures and characterized its pharmacokinetics. In NHPs (n=5) that self-administered midazolam (0.01 or 0.032 mg/kg/infusion), CBD (0.1-3.2 mg/kg/infusion) failed to maintain responding above vehicle levels. CBD maintained very modest levels of self-administration in rats (n=7-8) that self-administered heroin (0.015 mg/kg/infusion) and did not increase drug-lever responding, up to a dose of 150 mg/kg (p.o.), in rats (n=6) trained to discriminate 0.5 mg/kg (i.p.) midazolam. In juvenile (5-6 weeks old) and adult (10-11 weeks old) male and female rats, discontinuation of chronic treatment (twice daily for 20 days) with an oral formulation of CBD (20 or 100 mg/kg, p.o.) did not reliably produce signs of withdrawal. Pharmacokinetic studies confirmed that the dosing regimens used in these studies resulted in therapeutically relevant plasma levels. Taken together, the lack of reliable self-administration, the failure to increase drug-lever responding in rats trained to discriminate midazolam, and the absence of withdrawal signs upon discontinuation of chronic treatment indicate that CBD has very low abuse potential and is unlikely to produce physical dependence. Significance Statement Legalization of cannabis across the United States and elsewhere has led to intense investigation into the safety and therapeutic potential of cannabis and its constituent materials, including cannabidiol (CBD). Results of these preclinical abuse potential studies on CBD indicate no rewarding properties, physical dependence potential, or similarity to a benzodiazepine or THC. Together with data from in vitro pharmacology and human abuse potential studies, the abuse potential of Epidiolex in humans is likely to be negligible.

Rapamycin-induced hyperglycemia is associated with exacerbated age-related osteoarthritis

Background

The objective of this study was to determine if mechanistic target of rapamycin (mTOR) inhibition with or without AMP-activated protein kinase (AMPK) activation can protect against primary, age-related OA.

Design

Dunkin-Hartley guinea pigs develop mild primary OA pathology by 5 months of age that progresses to moderate OA by 8 months of age. At 5 months, guinea pigs served as young control (n = 3) or were fed either a control diet (n = 8), a diet enriched with the mTOR-inhibitor rapamycin (Rap, 14 ppm, n = 8), or Rap with the AMPK-activator metformin (Rap+Met, 1000 ppm, n = 8) for 12 weeks. Knee joints were evaluated by OARSI scoring, micro-computed tomography, and immunohistochemistry. Glenohumeral articular cartilage was collected for western blotting.

Results

Rap- and Rap+Met-treated guinea pigs displayed lower body weight than control. Rap and Rap+Met inhibited articular cartilage mTORC1 but not mTORC2 signaling. Rap+Met, but not Rap alone, stimulated AMPK. Despite lower body weight and articular cartilage mTORC1 inhibition, Rap- and Rap+Met-treated guinea pigs had greater OA severity in the medial tibial plateau due to articular cartilage structural damage and/or proteoglycan loss. Rap and Rap+Met increased plasma glucose compared to control. Plasma glucose concentration was positively correlated with proteoglycan loss, suggesting hyperglycemic stress after Rap treatment was related to worsened OA.

Conclusions

This is the first study to show that Rap induced increase in plasma glucose was associated with greater OA severity. Further, articular cartilage mTORC1 inhibition and bodyweight reduction by dietary Rap and Rap+Met did not appear to protect against primary OA during the prevailing hyperglycemia.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13075-021-02637-1.

17-a-estradiol late in life extends lifespan in aging UM-HET3 male mice; nicotinamide riboside and three other drugs do not affect lifespan in either sex

In genetically heterogeneous mice produced by the CByB6F1 x C3D2F1 cross, the "non-feminizing" estrogen, 17-α-estradiol (17aE2), extended median male lifespan by 19% (p < 0.0001, log-rank test) and 11% (p = 0.007) when fed at 14.4 ppm starting at 16 and 20 months, respectively. 90th percentile lifespans were extended 7% (p = 0.004, Wang-Allison test) and 5% (p = 0.17). Body weights were reduced about 20% after starting the 17aE2 diets. Four other interventions were tested in males and females: nicotinamide riboside, candesartan cilexetil, geranylgeranylacetone, and MIF098. Despite some data suggesting that nicotinamide riboside would be effective, neither it nor the other three increased lifespans significantly at the doses tested. The 17aE2 results confirm and extend our original reports, with very similar results when started at 16 months compared with mice started at 10 months of age in a prior study. The consistently large lifespan benefit in males, even when treatment is started late in life, may provide information on sex-specific aspects of aging.

Phosphatidylethanol in whole blood of rhesus monkeys correlates with ethanol consumption

BACKGROUND

Phosphatidylethanol (PEth) homologs are ethanol metabolites used to identify and monitor alcohol drinking in humans. In this study, we measured levels of the 2 most abundant homologs, PEth 16:0/18:1 and PEth 16:0/18:2, in whole blood samples from rhesus macaque monkeys that drank ethanol daily ad libitum to assess the relationship between PEth levels and recent ethanol exposure in this animal model.

METHODS

Blood samples were obtained from The Monkey Alcohol Tissue Research Resource. The monkeys were first induced to consume 4% (w/v) ethanol in water from a panel attached to their home cage. Then, monkeys were allowed to drink ethanol and water ad libitum 22 h daily for 12 months and the daily amount of ethanol each monkey consumed was measured. Whole, uncoagulated blood was collected from each animal at the end of the entire experimental procedure. PEth 16:0/18:1 and PEth 16:0/18:2 levels were analyzed by HPLC with tandem mass spectrometry, and the ethanol consumed during the preceding 14 days was measured. Combined PEth was the sum of the concentrations of both homologs.

RESULTS

Our results show that (1) PEth accumulates in the blood of rhesus monkeys after ethanol consumption; (2) PEth homolog levels were correlated with the daily average ethanol intake during the 14-day period immediately preceding blood collection; (3) the application of established human PEth 16:0/18:1 cutoff concentrations indicative of light social or no ethanol consumption (<20 ng/ml), moderate ethanol consumption (≥ 20 and < 200 ng/ml) and heavy ethanol consumption (≥ 200 ng/ml) predicted significantly different ethanol intake in these animals. PEth homologs were not detected in ethanol-naïve controls.

CONCLUSIONS

This study confirms that PEth is a sensitive biomarker for ethanol consumption in rhesus macaque monkeys. This nonhuman primate model may prove useful in evaluating sources of variability previously shown to exist between ethanol consumption and PEth homolog levels among humans.

Rapamycin Extends Life Span in ApcMin/+ Colon Cancer FAP Model

BACKGROUND

We previously showed that lifelong rapamycin treatment of short-lived ApcMin/+ mice, a model for familial adenomatous polyposis, resulted in a normal lifespan. ApcMin/+ mice develop colon polyps with a low frequency but can be converted to a colon cancer model by dextran sodium sulfate (DSS) treatments (ApcMin/+-DSS model).

MATERIALS AND METHODS

We asked, what effect would pretreatment of ApcMin/+ mice with chronic rapamycin prior to DSS exposure have on survival and colonic neoplasia?

RESULTS

Forty-two ppm enteric formulation of rapamycin diet exacerbated the temporary weight loss associated with DSS treatment in both sexes. However, our survival studies showed that chronic rapamycin treatment significantly extended lifespan of ApcMin/+-DSS mice (both sexes) by reductions in colon neoplasia and prevention of anemia. Rapamycin also had prophylactic effects on colon neoplasia induced by azoxymethane and DSS in C57BL/6 males and females. Immunoblot assays showed the expected inhibition of complex 1 of mechanistic or mammalian target of rapamycin (mTORC1) and effectors (S6K→rpS6 and S6K→eEF2K→eEF2) in colon by lifelong rapamycin treatments. To address the question of cell types affected by chronic enteric rapamycin treatment, immunohistochemistry analyses demonstrated that crypt cells had a prominent reduction in rpS6 phosphorylation and increase in eEF2 phosphorylation relative controls.

CONCLUSION

These data indicate that enteric rapamycin prevents or delays colon neoplasia in ApcMin/+-DSS mice through inhibition of mTORC1 in the crypt cells.

Canagliflozin extends life span in genetically heterogeneous male but not female mice

Canagliflozin (Cana) is an FDA-approved diabetes drug that protects against cardiovascular and kidney diseases. It also inhibits the sodium glucose transporter 2 by blocking renal reuptake and intestinal absorption of glucose. In the context of the mouse Interventions Testing Program, genetically heterogeneous mice were given chow containing Cana at 180 ppm at 7 months of age until their death. Cana extended median survival of male mice by 14%. Cana also increased by 9% the age for 90th percentile survival, with parallel effects seen at each of 3 test sites. Neither the distribution of inferred cause of death nor incidental pathology findings at end-of-life necropsies were altered by Cana. Moreover, although no life span benefits were seen in female mice, Cana led to lower fasting glucose and improved glucose tolerance in both sexes, diminishing fat mass in females only. Therefore, the life span benefit of Cana is likely to reflect blunting of peak glucose levels, because similar longevity effects are seen in male mice given acarbose, a diabetes drug that blocks glucose surges through a distinct mechanism, i.e., slowing breakdown of carbohydrate in the intestine. Interventions that control daily peak glucose levels deserve attention as possible preventive medicines to protect from a wide range of late-life neoplastic and degenerative diseases.

The SGLT2 inhibitor canagliflozin extends median life span of male mice but does not increase life span of female mice.

Rapamycin-mediated mouse lifespan extension: Late-life dosage regimes with sex-specific effects

To see if variations in timing of rapamycin (Rapa), administered to middle aged mice starting at 20 months, would lead to different survival outcomes, we compared three dosing regimens. Initiation of Rapa at 42 ppm increased survival significantly in both male and female mice. Exposure to Rapa for a 3‐month period led to significant longevity benefit in males only. Protocols in which each month of Rapa treatment was followed by a month without Rapa exposure were also effective in both sexes, though this approach was less effective than continuous exposure in female mice. Interpretation of these results is made more complicated by unanticipated variation in patterns of weight gain, prior to the initiation of the Rapa treatment, presumably due to the use of drug‐free food from two different suppliers. The experimental design included tests of four other drugs, minocycline, β‐guanidinopropionic acid, MitoQ, and 17‐dimethylaminoethylamino‐17‐demethoxygeldanamycin (17‐DMAG), but none of these led to a change in survival in either sex.

Alcohol Use Disorder Masks the Effects of Childhood Adversity, Lifetime Trauma, and Chronic Stress on Hypothalamic-Pituitary-Adrenal Axis Reactivity

BACKGROUND

Individuals with alcohol use disorder (AUD) and those who have experienced traumas or chronic stress exhibit dysregulated hypothalamic-pituitary-adrenal (HPA) axis reactivity. Whether and how trauma and stress histories interact with AUD to affect HPA axis reactivity has not been assessed.

METHODS

In the present study, 26 healthy male controls and 70 abstinent men with AUD were administered a pharmacologic probe [ovine corticotropin-releasing hormone (oCRH)] and psychosocial stressor to assess HPA axis reactivity. Plasma adrenocorticotropin hormone (ACTH) and cortisol were assessed every 10-20 minutes. Hierarchical clustering of multiple measures of trauma and stress identified 3 distinct clusters: childhood adversity, lifetime trauma, and chronic stress. General linear model procedures were used to examine main effects of group (AUD/control) and interaction effects of the 3 clusters upon net-integrated ACTH and cortisol response.

RESULTS

We found that higher levels of childhood adversity, lifetime trauma, and chronic stress were each associated with blunted oCRH-induced ACTH reactivity in controls, but not in the AUD group. Recent chronic stress within the prior 6 months had the strongest influence upon ACTH reactivity in the control group, and lifetime trauma, the least.

CONCLUSIONS

Childhood adversity, lifetime trauma, and chronic stress likely exert persistent, measurable effects upon HPA axis functioning in healthy controls. This association appears to be masked in individuals with AUD, potentially confounding studies examining the effects of stress, adversity, and/or trauma upon the HPA axis in this population during the protracted withdrawal phase of recovery. Future work targeting stress exposure and reactivity should consider the heightened effect of previous alcohol use relative to past adversity and trauma.

mTOR drives cerebrovascular, synaptic, and cognitive dysfunction in normative aging

Cerebrovascular dysfunction and cognitive decline are highly prevalent in aging, but the mechanisms underlying these impairments are unclear. Cerebral blood flow decreases with aging and is one of the earliest events in the pathogenesis of Alzheimer's disease (AD). We have previously shown that the mechanistic/mammalian target of rapamycin (mTOR) drives disease progression in mouse models of AD and in models of cognitive impairment associated with atherosclerosis, closely recapitulating vascular cognitive impairment. In the present studies, we sought to determine whether mTOR plays a role in cerebrovascular dysfunction and cognitive decline during normative aging in rats. Using behavioral tools and MRI-based functional imaging, together with biochemical and immunohistochemical approaches, we demonstrate that chronic mTOR attenuation with rapamycin ameliorates deficits in learning and memory, prevents neurovascular uncoupling, and restores cerebral perfusion in aged rats. Additionally, morphometric and biochemical analyses of hippocampus and cortex revealed that mTOR drives age-related declines in synaptic and vascular density during aging. These data indicate that in addition to mediating AD-like cognitive and cerebrovascular deficits in models of AD and atherosclerosis, mTOR drives cerebrovascular, neuronal, and cognitive deficits associated with normative aging. Thus, inhibitors of mTOR may have potential to treat age-related cerebrovascular dysfunction and cognitive decline. Since treatment of age-related cerebrovascular dysfunction in older adults is expected to prevent further deterioration of cerebral perfusion, recently identified as a biomarker for the very early (preclinical) stages of AD, mTOR attenuation may potentially block the initiation and progression of AD.

Acarbose improves health and lifespan in aging HET3 mice

To follow-up on our previous report that acarbose (ACA), a drug that blocks postprandial glucose spikes, increases mouse lifespan, we studied ACA at three doses: 400, 1,000 (the original dose), and 2,500 ppm, using genetically heterogeneous mice at three sites. Each dose led to a significant change (by log-rank test) in both sexes, with larger effects in males, consistent with the original report. There were no significant differences among the three doses. The two higher doses produced 16% or 17% increases in median longevity of males, but only 4% or 5% increases in females. Age at the 90th percentile was increased significantly (8%-11%) in males at each dose, but was significantly increased (3%) in females only at 1,000 ppm. The sex effect on longevity is not explained simply by weight or fat mass, which were reduced by ACA more in females than in males. ACA at 1,000 ppm reduced lung tumors in males, diminished liver degeneration in both sexes and glomerulosclerosis in females, reduced blood glucose responses to refeeding in males, and improved rotarod performance in aging females, but not males. Three other interventions were also tested: ursolic acid, 2-(2-hydroxyphenyl) benzothiazole (HBX), and INT-767; none of these affected lifespan at the doses tested. The acarbose results confirm and extend our original report, prompt further attention to the effects of transient periods of high blood glucose on aging and the diseases of aging, including cancer, and should motivate studies of acarbose and other glucose-control drugs in humans.

Effects of intravenous AICAR (5-aminoimidazole-4-carboximide riboside) administration on insulin signaling and resistance in premature baboons, Papio sp

Premature baboons exhibit peripheral insulin resistance and impaired insulin signaling. 5' AMP-activated protein kinase (AMPK) activation improves insulin sensitivity by enhancing glucose uptake (via increased glucose transporter type 4 [GLUT4] translocation and activation of the extracellular signal-regulated kinase [ERK]/ atypical protein kinase C [aPKC] pathway), and increasing fatty acid oxidation (via inhibition of acetyl-CoA carboxylase 1 [ACC]), while downregulating gluconeogenesis (via induction of small heterodimer partner [SHP] and subsequent downregulation of the gluconeogenic enzymes: phosphoenolpyruvate carboxykinase [PEPCK], glucose 6-phosphatase [G6PASE], fructose- 1,6-bisphosphatase 1 [FBP1], and forkhead box protein 1 [FOXO1]). The purpose of this study was to investigate whether pharmacologic activation of AMPK with AICAR (5-aminoimidazole-4-carboximide riboside) administration improves peripheral insulin sensitivity in preterm baboons. 11 baboons were delivered prematurely at 125±2 days (67%) gestation. 5 animals were randomized to receive 5 days of continuous AICAR infusion at a dose of 0.5 mg·g-1·day-1. 6 animals were in the placebo group. Euglycemic hyperinsulinemic clamps were performed at 5±2 and 14±2 days of life. Key molecules potentially altered by AICAR (AMPK, GLUT4, ACC, PEPCK, G6PASE, FBP1, and FOXO1), and the insulin signaling molecules: insulin receptor (INSR), insulin receptor substrate 1 (IRS-1), protein kinase B (AKT), and peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC1α) were measured using RT-PCR and western blotting. AICAR infusion did not improve whole body insulin-stimulated glucose disposal in preterm baboons (12.8±2.4 vs 12.4±2.0 mg/(kg·min), p = 0.8, placebo vs AICAR). One animal developed complications during treatment. In skeletal muscle, AICAR infusion did not increase phosphorylation of ACC, AKT, or AMPK whereas it increased mRNA expression of ACACA (ACC), AKT, and PPARGC1A (PGC1α). In the liver, INSR, IRS1, G6PC3, AKT, PCK1, FOXO1, and FBP1 were unchanged, whereas PPARGC1A mRNA expression increased after AICAR infusion. This study provides evidence that AICAR does not improve insulin sensitivity in premature euglycemic baboons, and may have adverse effects.

Intensive prolonged exposure therapy for combat-related posttraumatic stress disorder: Design and methodology of a randomized clinical trial

Combat-related posttraumatic stress disorder (PTSD) is the most common psychological health condition in military service members and veterans who have deployed to the combat theater since September 11, 2001. One of the highest research priorities for the Department of Defense and the Department of Veterans Affairs is to develop and evaluate the most efficient and efficacious treatments possible for combat-related PTSD. However, the treatment of combat-related PTSD in military service members and veterans has been significantly more challenging than the treatment of PTSD in civilians. Randomized clinical trials have demonstrated large posttreatment effect sizes for PTSD in civilian populations. However, recent randomized clinical trials of service members and veterans have achieved lesser reductions in PTSD symptoms. These results suggest that combat-related PTSD is unique. Innovative approaches are needed to augment established evidence-based treatments with targeted interventions that address the distinctive elements of combat-related traumas. This paper describes the design, methodology, and protocol of a randomized clinical trial to compare two intensive prolonged exposure therapy treatments for combat-related PTSD in active duty military service members and veterans and that can be administered in an acceptable, efficient manner in this population. Both interventions include intensive daily treatment over a 3-week period and a number of treatment enhancements hypothesized to result in greater reductions in combat-related PTSD symptoms. The study is designed to advance the delivery of care for combat-related PTSD by developing and evaluating the most potent treatments possible to reduce PTSD symptomatology and improve psychological, social, and occupational functioning.

Pharmacokinetics of Phosphatidylethanol 16:0/20:4 in Human Blood After Alcohol Intake

BACKGROUND

The purpose of this study was to characterize the pharmacokinetics of the phosphatidylethanol (PEth) 16:0/20:4 homolog in uncoagulated human blood samples taken from 18 participants in a clinical laboratory setting after consumption of 2 standard doses of ethanol (EtOH).

METHODS

Male and female participants received either 0.4 or 0.8 g/kg oral doses of EtOH during a 15-minute period. Blood samples were collected before and throughout 6 hours immediately after alcohol administration and then again at days 2, 4, 7, 11, and 14 of the follow-up period. PEth 16:0/20:4 levels were quantified by high-performance liquid chromatography with tandem mass spectrometry detection.

RESULTS

(i) The increase in PEth 16:0/20:4 from baseline to maximum concentration was less than that of PEth 16:0/18:1 or PEth 16:0/18:2 homologs during the 6-hour period after EtOH administration; (ii) the mean half-life of PEth 16:0/20:4 was 2.1 ± 3 (SD) days, which was shorter than the mean half-life of either PEth 16:0/18:1 or PEth 16:0/18:2, 7.6 ± 3 (SD) or 6.8 ± 4 (SD) days, respectively.

CONCLUSIONS

The pharmacokinetics of PEth 16:0/20:4 in whole blood samples is detectable after alcohol consumption and differs in amount synthesized and rate of elimination versus PEth 16:0/18:1 and 16:0/18:2. Measuring the concentrations of these 3 homologs has the potential to provide more information about the amount and time frame of alcohol consumption than any one alone.

The long-term effect of maternal dietary protein restriction on 5-HT1A receptor function and behavioral responses to stress in adulthood

Maternal nutrition impacts fetal development, and may play a role in determining resilience to stress and vulnerability to stress-precipitated psychiatric disorders, such as anxiety and depression. In this study, we examined the effect of a reduction in maternal dietary protein during pregnancy on the brain neurochemistry and behavior of offspring. We focused specifically on the serotonin system, the 5-HT_1A receptor and the responsivity of offspring as adults to stress. Dams were fed either a low protein diet (10% protein by weight) or isocaloric control diet (20% protein by weight). The low protein diet did not alter maternal food intake and body weight, or litter size and the average birth weight of male or female littermates. 5-HT_1A receptor function, as measured by quantitative autoradiography of 8-OH-DPAT (1 μM)-stimulated [³⁵S]GTPγS binding, was markedly reduced in hippocampus of weanling female, but not male offspring (postnatal day, PND 21) of dams fed the low protein diet. The number of serotonergic cell bodies in the rostral raphe, and 5-HT metabolism in the limbic system of weanling offspring was not altered by maternal low protein diet. The deficit in hippocampal 5-HT_1A receptor function observed in weanling female offspring persisted into adulthood (PND 112), and was accompanied by an increased sensitivity to stress, specifically increased immobility during a 15-minute forced swim challenge and increased anorexia following 30-minute restraint (PND 97-100). The present work begins to uncover important future directions for understanding the early developmental origins of resilience to stress, and factors that may put individuals at greater risk for stress-related psychiatric disorders.

Differences in the Synthesis and Elimination of Phosphatidylethanol 16:0/18:1 and 16:0/18:2 After Acute Doses of Alcohol

BACKGROUND

The purpose of this study was to examine the synthesis and elimination of phosphatidylethanol (PEth) 16:0/18:1 and 16:0/18:2 following the consumption of alcohol among 56 light and heavy drinkers.

METHODS

A transdermal alcohol monitor was used to promote alcohol absence 7 days prior, and 14 days after, alcohol consumption in the laboratory. Participants consumed a 0.4 or 0.8 g/kg dose of alcohol in 15 minutes. Blood and breath samples were collected before, at various times up to 360 minutes postconsumption, and 2, 4, 7, 11, and 14 days after alcohol consumption. Initial rates of PEth synthesis, 360 minutes area under the PEth pharmacokinetic curves (AUCs), and elimination half-lives were determined.

RESULTS

(i) Nonzero PEth levels were observed before alcohol dosing for most participants, despite 7 days of alcohol use monitoring; (ii) 0.4 and 0.8 g/kg doses of alcohol produced proportional increases in PEth levels in all but 1 participant; (iii) the initial rate of synthesis of both PEth homologues did not differ between the 2 doses, but was greater for PEth 16:0/18:2 than PEth 16:0/18:1 at both doses; (iv) the mean AUC of both PEth homologues was higher at 0.8 g/kg than at 0.4 g/kg; (v) the mean AUC of 16:0/18:2 was greater than that of PEth 16:0/18:1 at both alcohol doses; (vi) the mean half-life of PEth 16:0/18:1 was longer than that of PEth 16:0/18:2 (7.8 ± 3.3 [SD] days and 6.4 ± 5.0 [SD] days, respectively); and (vii) there were no sex differences in PEth 16:0/18:1 or 16:0/18:2 pharmacokinetics.

CONCLUSIONS

The results of this study support the use of PEth 16:0/18:1 and 16:0/18:2 as biomarkers for alcohol consumption. Because of consistent pharmacokinetic differences, the levels of these 2 PEth homologues may provide more information regarding the quantity and recentness of alcohol consumption than either alone.

A randomized control trial to establish the feasibility and safety of rapamycin treatment in an older human cohort: Immunological, physical performance, and cognitive effects

Inhibition of the mechanistic target of rapamycin (mTOR) pathway by rapamycin (RAPA), an FDA-approved immunosuppressive drug used as a clinical therapy to prevent solid organ allograft rejection, enhances longevity in mice. Importantly, RAPA was efficacious even when initiated in relatively old animals, suggesting that mTOR inhibition could potentially slow the progression of aging-associated pathologies in older humans (Harrison et al., 2009; Miller et al., 2011). However, the safety and tolerability of RAPA in older human subjects have not yet been demonstrated. Towards this end, we undertook a placebo-controlled pilot study in 25 generally healthy older adults (aged 70-95 years); subjects were randomized to receive either 1 mg RAPA or placebo daily. Although three subjects withdrew, 11 RAPA and 14 controls completed at least 8 weeks of treatment and were included in the analysis. We monitored for changes that would indicate detrimental effects of RAPA treatment on metabolism, including both standard clinical laboratory assays (CBC, CMP, HbA1c) and oral glucose tolerance tests (OGTTs). We also monitored parameters typically associated with aging that could potentially be modified by RAPA; these included cognitive function which was assessed by three different tools: Executive Interview-25 (EXIT25); Saint Louis University Mental Status Exam (SLUMS); and Texas Assessment of Processing Speed (TAPS). In addition, physical performance was measured by handgrip strength and 40-foot timed walks. Lastly, changes in general parameters of healthy immune aging, including serum pro-inflammatory cytokine levels and blood cell subsets, were assessed. Five subjects reported potential adverse side effects; in the RAPA group, these were limited to facial rash (1 subject), stomatitis (1 subject) and gastrointestinal issues (2 subjects) whereas placebo treated subjects only reported stomatitis (1 subject). Although no other adverse events were reported, statistically significant decrements in several erythrocyte parameters including hemoglobin (HgB) and hematocrit (Hct) as well as in red blood cell count (RBC), red blood cell distribution width (RDW), mean corpuscular volume (MCV), and mean corpuscular hemoglobin (MCH) were observed in the RAPA-treatment group. None of these changes manifested clinically significant effects during the short duration of this study. Similarly, no changes were noted in any other clinical laboratory, cognitive, physical performance, or self-perceived health status measure over the study period. Immune parameters were largely unchanged as well, possibly due to the advanced ages of the cohort (70-93 years; mean age 80.5). RAPA-associated increases in a myeloid cell subset and in T_REGS were detected, but changes in most other PBMC cell subsets were not statistically significant. Importantly, the OGTTs revealed no RAPA-induced change in blood glucose concentration, insulin secretion, and insulin sensitivity. Thus, based on the results of our pilot study, it appears that short-term RAPA treatment can be used safely in older persons who are otherwise healthy; a trial with a larger sample size and longer treatment duration is warranted.

The discriminative stimulus effects of i.v. nicotine in rhesus monkeys: Pharmacokinetics and apparent pA2 analysis with dihydro-β-erythroidine

Quantitative analysis of antagonism is infrequently used to identify nAChRs mediating behavioral effects. Here, nicotine (0.032 mg/kg i.v.) was established as a discriminative stimulus in rhesus monkeys responding under a fixed ratio 5 schedule; pharmacokinetics and underlying nAChR mechanism(s) were examined. When measured up to 4 h in venous blood, the training dose resulted in the following mean pharmacokinetic parameters: nicotine C_max = 71.7 ng/ml, t_1/2 = 116 min, and clearance = 6.25 ml/min/kg; cotinine C_max = 191 ng/ml; and 3OH-cotinine C_max = 63 ng/ml. The ED₅₀ value of nicotine to produce discriminative stimulus effects was 0.013 mg/kg. Epibatidine and varenicline increased drug-lever responding to 97% and 95%, respectively (ED₅₀ values = 0.00015 and 0.031 mg/kg, respectively), whereas cocaine, midazolam, and morphine produced no more than 28% drug-appropriate responding. Mecamylamine and dihydro-β-erythroidine (DHβE) dose-dependently attenuated the discriminative stimulus effects of the nicotine training dose, whereas methyllycaconitine (MLA) did not. DHβE (0.1 and 0.32) produced rightward shifts of the nicotine and varenicline dose-response functions; Schild plots fitted through individual data resulted in slopes that were not different from unity; the apparent pA₂ calculated for DHβE did not significantly differ in the presence of nicotine (6.58) or varenicline (6.45). Compared to human cigarette smoking, nicotine blood levels after 0.032 mg/kg nicotine i.v. took a similar time to reach maximal concentration, levels at Cmax were similar to smoking 2-3 cigarettes, while average nicotine levels were comparable to smoking 5-6 cigarettes. Apparent pA₂ analysis with DHβE under these conditions is consistent with nicotine and varenicline acting through the same nAChRs to produce discriminative stimulus effects.

Attenuated nicotine-like effects of varenicline but not other nicotinic ACh receptor agonists in monkeys receiving nicotine daily

BACKGROUND AND PURPOSE

Chronic treatment can differentially impact the effects of pharmacologically related drugs that differ in receptor selectivity and efficacy.

EXPERIMENTAL APPROACH

The impact of daily nicotine treatment on the effects of nicotinic ACh receptor (nAChR) agonists was examined in two groups of rhesus monkeys discriminating nicotine (1.78 mg·kg-1 base weight) from saline. One group received additional nicotine treatment post-session (1.78 mg·kg-1 administered five times daily, each dose 2 h apart; i.e. Daily group), and the second group did not (Intermittent group).

KEY RESULTS

Daily repeated nicotine treatment produced a time-related increase in saliva cotinine. There was no significant difference in the ED50 values of the nicotine discriminative stimulus between the Daily and Intermittent group. Mecamylamine antagonized the effects of nicotine, whereas dihydro-β-erythroidine did not. Midazolam produced 0% nicotine-lever responding. The nAChR agonists epibatidine, RTI-36, cytisine and varenicline produced >96% nicotine-lever responding in the Intermittent group. The respective maximum effects in the Daily group were 100, 72, 59 and 28%, which shows that the ability of varenicline to produce nicotine-like responding was selectively decreased in the Daily as compared with the Intermittent group. When combined with nicotine, both varenicline and cytisine increased the potency of nicotine to produce discriminative stimulus effects.

CONCLUSION AND IMPLICATIONS

Nicotine treatment has a greater impact on the sensitivity to the effects of varenicline as compared with some other nAChR agonists. Collectively, these results strongly suggest that varenicline differs from nicotine in its selectivity for multiple nAChR subtypes.

Phosphatidylethanol in Postmortem Brain and Serum Ethanol at Time of Death

BACKGROUND

Phosphatidylethanol (PEth) is a metabolite of ethanol (EtOH), and its concentration in whole blood samples is a direct biomarker of alcohol consumption. Because PEth is also present in the brain and incorporated in lipid membranes, it can be used to classify deceased individuals on alcohol consumption status at the time of death. The purpose of this study was to detect PEth homologs in postmortem brains of individuals known to have had alcohol use disorder (AUD) and to determine the relationship between serum alcohol at the time of death and PEth in the cerebellum (CE) and orbital frontal cortex (OFC).

METHODS

Postmortem brain was collected and stored according to standard protocol. Psychiatric symptoms experienced prior to death were obtained by next of kin psychological autopsy to categorize subjects. Thirty male subjects were chosen for analyses: 10 with AUD with positive serum EtOH levels present at time of autopsy (AUD-W), 10 with AUD without positive serum EtOH levels (AUD-WO), and 10 controls. PEth 16:0/18:1 and 16:0/18:2 were quantified in 50 mg of CE and OFC of human postmortem brain using HPLC and mass spectrometric detection (triple quadrupole).

RESULTS

Results of this study were as follows: (i) PEth 16:0/18:1 and 16:0/18:2 were detected in the CE and OFC of all subjects diagnosed with AUD, (ii) PEth 16:0/18:1 levels were about 10-fold higher than PEth 16:0/18:2 in all subjects and both areas of brain, (iii) AUD-W subjects had higher PEth homolog levels in CE and OFC than controls and AUD-WO subjects, (iv) PEth 16:0/18:1, but not PEth 16:0/18:2, levels in CE and OFC of AUD-W subjects correlated significantly with serum EtOH levels at the time of death.

CONCLUSIONS

Quantification of combined PEth homolog levels in postmortem human brain is a good candidate as a diagnostic factor to classify drinking status, especially for those with AUD at the time of death. For alcohol research studies with postmortem brain, verification of drinking status is essential.

Longer lifespan in male mice treated with a weakly estrogenic agonist, an antioxidant, an α-glucosidase inhibitor or a Nrf2-inducer

The National Institute on Aging Interventions Testing Program (ITP) evaluates agents hypothesized to increase healthy lifespan in genetically heterogeneous mice. Each compound is tested in parallel at three sites, and all results are published. We report the effects of lifelong treatment of mice with four agents not previously tested: Protandim, fish oil, ursodeoxycholic acid (UDCA) and metformin - the latter with and without rapamycin, and two drugs previously examined: 17-α-estradiol and nordihydroguaiaretic acid (NDGA), at doses greater and less than used previously. 17-α-estradiol at a threefold higher dose robustly extended both median and maximal lifespan, but still only in males. The male-specific extension of median lifespan by NDGA was replicated at the original dose, and using doses threefold lower and higher. The effects of NDGA were dose dependent and male specific but without an effect on maximal lifespan. Protandim, a mixture of botanical extracts that activate Nrf2, extended median lifespan in males only. Metformin alone, at a dose of 0.1% in the diet, did not significantly extend lifespan. Metformin (0.1%) combined with rapamycin (14 ppm) robustly extended lifespan, suggestive of an added benefit, based on historical comparison with earlier studies of rapamycin given alone. The α-glucosidase inhibitor, acarbose, at a concentration previously tested (1000 ppm), significantly increased median longevity in males and 90th percentile lifespan in both sexes, even when treatment was started at 16 months. Neither fish oil nor UDCA extended lifespan. These results underscore the reproducibility of ITP longevity studies and illustrate the importance of identifying optimal doses in lifespan studies.

Characterization of the Pharmacokinetics of Phosphatidylethanol 16:0/18:1 and 16:0/18:2 in Human Whole Blood After Alcohol Consumption in a Clinical Laboratory Study

BACKGROUND

The purpose of this study was to characterize the pharmacokinetics of 2 homologues of phosphatidylethanol (PEth) and their combined total in uncoagulated, whole blood samples taken from participants in a human clinical laboratory study after consumption of low doses of ethanol (EtOH).

METHODS

As part of a larger study, 14 male and 13 female participants received either 0.25 or 0.50 g/kg oral doses of EtOH during a 15-minute period. Blood samples were collected before and throughout 6 hours after each EtOH dose on the day of consumption and then every 3 days during the next 14 days. PEth 16:0/18:1 and PEth 16:0/18:2 levels were quantified in blood samples by HPLC/MS/MS and reported separately or as their combined total (combined PEth). Breath alcohol concentrations (BrACs) were measured concurrently with each blood collection. Transdermal alcohol concentrations were measured every 30 minutes during the entire 22-day study to confirm the absence of drinking during a 7-day period before and the 14-day period after EtOH consumption.

RESULTS

(i) Single doses of 0.25 and 0.50 g EtOH/kg produced proportional increases in BrAC and combined PEth levels of all participants; (ii) the areas under the curve (AUCs) for each participant's BrAC levels during the 6-hour period after EtOH administration were correlated with AUCs of cPEth (calculated as the AUC of the increase above baseline for combined PEth); (iii) the mean half-life of combined PEth, determined during the 14-day period after EtOH consumption, was 4.6 ± 3.5 (SD) days (range: 1.0 to 13.1 days).

CONCLUSIONS

Combined PEth is a sensitive biomarker for the identification of relatively low levels of EtOH consumption. The measurement of these 2 homologues may provide additional sensitivity to identify low levels of drinking.

Lorcaserin Reduces the Discriminative Stimulus and Reinforcing Effects of Cocaine in Rhesus Monkeys

Cocaine abuse and obesity are serious public health problems, and studies suggest that both dopamine and serotonin systems are involved in regulating the consumption of drugs and food. Lorcaserin has serotonin (5-HT)2C receptor agonist actions, is approved by the U.S. Food and Drug Administration for treating obesity, and might be effective for treating cocaine abuse. These studies characterized the pharmacokinetic and behavioral profiles of lorcaserin (intragastric administration) and determined the effectiveness of lorcaserin to alter discriminative stimulus and reinforcing effects of cocaine (intravenous administration) in rhesus monkeys. Administered acutely, lorcaserin dose-dependently increased the occurrence of yawning while decreasing spontaneous activity and operant responding for food. These effects appeared within 30-60 minutes of administration and began to dissipate by 240 minutes, a time course closely matching plasma concentrations of lorcaserin. In monkeys discriminating cocaine from saline, lorcaserin alone did not occasion cocaine-appropriate responding but shifted the cocaine dose-response curve to the right and down in two of three monkeys. When administered acutely, lorcaserin dose-dependently decreased the rate at which monkeys responded for infusions of cocaine. When administered chronically, 3.2 mg/kg lorcaserin reduced the rate of cocaine-maintained responding by 50% for the duration of a 14-day treatment period. Together, these results show that lorcaserin attenuates the discriminative stimulus effects of cocaine after acute administration and the reinforcing effects of cocaine after acute and repeated administration, consistent with the view that it might have utility in treating cocaine abuse.

Rapamycin Increases Mortality in db/db Mice, a Mouse Model of Type 2 Diabetes

We examined the effect of rapamycin on the life span of a mouse model of type 2 diabetes, db/db mice. At 4 months of age, male and female C57BLKSJ-lepr (db/db) mice (db/db) were placed on either a control diet, lacking rapamycin or a diet containing rapamycin and maintained on these diets over their life span. Rapamycin was found to reduce the life span of the db/db mice. The median survival of male db/db mice fed the control and rapamycin diets was 349 and 302 days, respectively, and the median survival of female db/db mice fed the control and rapamycin diets was 487 and 411 days, respectively. Adjusting for gender differences, rapamycin increased the mortality risk 1.7-fold in both male and female db/db mice. End-of-life pathological data showed that suppurative inflammation was the main cause of death in the db/db mice, which is enhanced slightly by rapamycin treatment.

Physiological and behavioral effects of amphetamine in BACE1(-/-) mice

β-Site APP-cleaving Enzyme 1 (BACE1) is a protease that has been linked to schizophrenia, a severe mental illness that is potentially characterized by enhanced dopamine (DA) release in the striatum. Here, we used acute amphetamine administration to stimulate neuronal activity and investigated the neurophysiological and locomotor-activity response in BACE1-deficient (BACE1(-/-) ) mice. We measured locomotor activity at baseline and after treatment with amphetamine (3.2 and 10 mg/kg). While baseline locomotor activity did not vary between groups, BACE1(-/-) mice exhibited reduced sensitivity to the locomotor-enhancing effects of amphetamine. Using high-performance liquid chromatography (HPLC) to measure DA and DA metabolites in the striatum, we found no significant differences in BACE1(-/-) compared with wild-type mice. To determine if DA neuron excitability is altered in BACE1(-/-) mice, we performed patch-clamp electrophysiology in putative DA neurons from brain slices that contained the substantia nigra. Pacemaker firing rate was slightly increased in slices from BACE1(-/-) mice. We next measured G protein-coupled potassium currents produced by activation of D2 autoreceptors, which strongly inhibit firing of these neurons. The maximal amplitude and decay times of D2 autoreceptor currents were not altered in BACE1(-/-) mice, indicating no change in D2 autoreceptor-sensitivity and DA transporter-mediated reuptake. However, amphetamine (30 µm)-induced potassium currents produced by efflux of DA were enhanced in BACE1(-/-) mice, perhaps indicating increased vesicular DA content in the midbrain. This suggests a plausible mechanism to explain the decreased sensitivity to amphetamine-induced locomotion, and provides evidence that decreased availability of BACE1 can produce persistent adaptations in the dopaminergic system.

Acute dietary tryptophan manipulation differentially alters social behavior, brain serotonin and plasma corticosterone in three inbred mouse strains

Clinical evidence indicates brain serotonin (5-HT) stores and neurotransmission may be inadequate in subpopulations of individuals with autism, and this may contribute to characteristically impaired social behaviors. Findings that depletion of the 5-HT precursor tryptophan (TRP) worsens autism symptoms support this hypothesis. Yet dietetic studies show and parents report that many children with autism consume less TRP than peers. To measure the impact of dietary TRP content on social behavior, we administered either diets devoid of TRP, with standard TRP (0.2 g%), or with 1% added TRP (1.2 g%) overnight to three mouse strains. Of these, BTBRT(+)Itpr3(tf)/J and 129S1/SvImJ consistently exhibit low preference for social interaction relative to C57BL/6. We found that TRP depletion reduced C57BL/6 and 129S social interaction preference, while TRP enhancement improved BTBR sociability (p < 0.05; N = 8-10). Subsequent marble burying did not differ among diets or strains. After behavior tests, brain TRP levels and plasma corticosterone were higher in TRP enhanced C57BL/6 and BTBR, while 5-HT levels were reduced in all strains by TRP depletion (p < 0.05; N = 4-10). Relative hyperactivity of BTBR and hypoactivity of 129S, evident in self-grooming and chamber entries during sociability tests, were uninfluenced by dietary TRP. Our findings demonstrate mouse sociability and brain 5-HT turnover are reduced by acute TRP depletion, and can be enhanced by TRP supplementation. This outcome warrants further basic and clinical studies employing biomarker combinations such as TRP metabolism and 5-HT regulated hormones to characterize conditions wherein TRP supplementation may best ameliorate sociability deficits.

Rapamycin-mediated lifespan increase in mice is dose and sex dependent and metabolically distinct from dietary restriction

Rapamycin, an inhibitor of mTOR kinase, increased median lifespan of genetically heterogeneous mice by 23% (males) to 26% (females) when tested at a dose threefold higher than that used in our previous studies; maximal longevity was also increased in both sexes. Rapamycin increased lifespan more in females than in males at each dose evaluated, perhaps reflecting sexual dimorphism in blood levels of this drug. Some of the endocrine and metabolic changes seen in diet-restricted mice are not seen in mice exposed to rapamycin, and the pattern of expression of hepatic genes involved in xenobiotic metabolism is also quite distinct in rapamycin-treated and diet-restricted mice, suggesting that these two interventions for extending mouse lifespan differ in many respects.

Acarbose, 17-α-estradiol, and nordihydroguaiaretic acid extend mouse lifespan preferentially in males

Four agents — acarbose (ACA), 17-α-estradiol (EST), nordihydroguaiaretic acid (NDGA), and methylene blue (MB) — were evaluated for lifespan effects in genetically heterogeneous mice tested at three sites. Acarbose increased male median lifespan by 22% (P < 0.0001), but increased female median lifespan by only 5% (P = 0.01). This sexual dimorphism in ACA lifespan effect could not be explained by differences in effects on weight. Maximum lifespan (90th percentile) increased 11% (P < 0.001) in males and 9% (P = 0.001) in females. EST increased male median lifespan by 12% (P = 0.002), but did not lead to a significant effect on maximum lifespan. The benefits of EST were much stronger at one test site than at the other two and were not explained by effects on body weight. EST did not alter female lifespan. NDGA increased male median lifespan by 8–10% at three different doses, with P-values ranging from 0.04 to 0.005. Females did not show a lifespan benefit from NDGA, even at a dose that produced blood levels similar to those in males, which did show a strong lifespan benefit. MB did not alter median lifespan of males or females, but did produce a small, statistically significant (6%, P = 0.004) increase in female maximum lifespan. These results provide new pharmacological models for exploring processes that regulate the timing of aging and late-life diseases, and in particular for testing hypotheses about sexual dimorphism in aging and health.

Distribution of venlafaxine, O-desmethylvenlafaxine, and O-desmethylvenlafaxine to venlafaxine ratio in postmortem human brain tissue

Venlafaxine (VEN) and its metabolite O-desmethylvenlafaxine (ODV) inhibit reuptake of serotonin and norepinephrine. This study examines whether VEN is differentially distributed in postmortem brain and examines relationships between brain and femoral blood concentrations from donors prescribed VEN for treatment of depression. Using high-pressure liquid chromatography-ultraviolet detection, VEN and ODV concentrations were measured in temporal, occipital, and cerebellar cortex of six postmortem brains. The ODV/VEN ratio was calculated as a relative measure of drug metabolism within each region where higher ratios indicated a greater conversion of VEN to ODV. Compared to the other regions examined, the cerebellum showed decreased VEN (p = 0.056), ODV (p = 0.006), and ODV/VEN (p = 0.027) ratios. In parts per million, VEN was higher in temporal and occipital cortex, but not cerebellum, as compared to femoral blood concentration. These observations suggest that VEN and ODV are differentially distributed in the brain, and metabolism of VEN to ODV may vary across brain regions.

Topiramate for the treatment of cocaine addiction: a randomized clinical trial

IMPORTANCE

No medication has been established as an efficacious treatment for cocaine dependence. We hypothesized that dual modulation of the mesocorticolimbic dopamine system by topiramate-a glutamate receptor antagonist and γ-aminobutyric acid receptor agonist-would result in efficacious treatment for cocaine dependence compared with placebo.

OBJECTIVE

To determine the efficacy of topiramate vs placebo as a treatment for cocaine dependence.

DESIGN, SETTING, AND PARTICIPANTS

Double-blind, randomized, placebo-controlled, 12-week trial of 142 cocaine-dependent adults in clinical research facilities at the University of Virginia between November 22, 2005, and July 25, 2011.

INTERVENTIONS

Topiramate (n = 71) or placebo (n = 71) in escalating doses from 50 mg/d to the target maintenance dose of 300 mg/d in weeks 6 to 12, combined with weekly cognitive-behavioral treatment.

MAIN OUTCOMES AND MEASURES

For the efficacy period, weeks 6 to 12, the primary outcome was the weekly difference from baseline in the proportion of cocaine nonuse days; the secondary outcome was urinary cocaine-free weeks, and exploratory outcomes included craving and self- and observer-rated global functioning on the Clinical Global Impression scales.

RESULTS

Using an intent-to-treat analysis, topiramate was more efficacious than placebo at increasing the weekly proportion of cocaine nonuse days, irrespective of whether missing data were not or were imputed conservatively to the baseline value (13.3% vs 5.3%, 95% CI for the estimated mean difference, 1.4%-14.6%, P = .02 or 8.9% vs 3.7%, 95% CI for the estimated mean difference, 0.2%-10.1%, P = .04, respectively). Topiramate also was associated, significantly more than placebo, with increasing the likelihood of urinary cocaine-free weeks (16.6% vs 5.8%; odds ratio, 3.21; 95% CI, 1.24-8.32; P = .02), as well as decreasing craving and improving observer-rated global functioning (all P < .05).

CONCLUSIONS AND RELEVANCE

Topiramate is more efficacious than placebo at increasing the mean weekly proportion of cocaine nonuse days and associated measures of clinical improvement among cocaine-dependent individuals.

Rapamycin extends life span of Rb1+/- mice by inhibiting neuroendocrine tumors

Chronic treatment of mice with an enterically released formulation of rapamycin (eRapa) extends median and maximum life span, partly by attenuating cancer. The mechanistic basis of this response is not known. To gain a better understanding of these in vivo effects, we used a defined preclinical model of neuroendocrine cancer, Rb1^+/− mice. Previous results showed that diet restriction (DR) had minimal or no effect on the lifespan of Rb1^+/− mice, suggesting that the beneficial response to DR is dependent on pRb1. Since long-term eRapa treatment may at least partially mimic chronic DR in lifespan extension, we predicted that it would have a minimal effect in Rb1^+/− mice. Beginning at 9 weeks of age until death, we fed Rb1^+/− mice a diet without or with eRapa at 14 mg/kg food, which results in an approximate dose of 2.24 mg/kg body weight per day, and yielded rapamycin blood levels of about 4 ng/ml. Surprisingly, we found that eRapa dramatically extended life span of both female and male Rb1^+/− mice, and slowed the appearance and growth of pituitary and decreased the incidence of thyroid tumors commonly observed in these mice. In this model, eRapa appears to act differently than DR, suggesting diverse mechanisms of action on survival and anti-tumor effects. In particular the beneficial effects of rapamycin did not depend on the dose of Rb1.

Duration of rapamycin treatment has differential effects on metabolism in mice

The evolutionarily conserved target of rapamycin (TOR) signaling controls growth, metabolism, and aging. In the first robust demonstration of pharmacologically-induced life extension in mammals, longevity was extended in mice treated with rapamycin, an inhibitor of mechanistic TOR (mTOR). However, detrimental metabolic effects of rapamycin treatment were also reported, presenting a paradox of improved survival despite metabolic impairment. How rapamycin extended lifespan in mice with such paradoxical effects was unclear. Here we show that detrimental effects of rapamycin treatment were only observed during the early stages of treatment. These effects were reversed or diminished in mice treated for 20 weeks, with better metabolic profiles, increased oxygen consumption and ketogenesis, and markedly enhanced insulin sensitivity. Thus, prolonged rapamycin treatment lead to beneficial metabolic alterations, consistent with life extension previously observed. Our findings provide a likely explanation of the "rapamycin paradox" and support the potential causal importance of these metabolic alterations in longevity.

Seizure susceptibility and epileptogenesis in a rat model of epilepsy and depression co-morbidity

Although a strong co-morbidity exists clinically between epilepsy and depression, the cause of this co-morbidity remains unknown, and a valid animal model is crucial for the identification of underlying mechanisms and the development of a screening tool for novel therapies. Although some rodent models of epilepsy have been reported to display behaviors relevant to affective disorders, the seizure susceptibility of animals prone to depression-like behavior has not been characterized. Toward this end, we assessed several forms of seizure sensitivity and epileptogenesis in rats selectively bred for vulnerability (Swim Lo-Active; SwLo) or resilience (Swim High-Active; SwHi) to depression-like phenotypes. The SwLo rats exhibit decreased motor activity in a swim test and other depression-like phenotypes, whereas the SwHi rats display increased motor activity in a swim test. SwLo rats exhibited a decreased latency to limbic motor seizures following acute pilocarpine administration in the absence of differences in pilocarpine pharmacokinetics, and also had a decreased threshold to tonic seizures induced by electroshock. Approximately half of the SwLo rats, but none of the SwHi rats, had spontaneous limbic motor seizures 5 weeks following pilocarpine-induced status epilepticus. While the number of stimulations required to achieve full amygdala and hippocampal electrical kindling were similar in the two rat lines, SwLo rats had a lower final hippocampal kindling threshold and more wet dog shakes during both amygdala and hippocampal kindling. Combined, these results indicate that SwLo rats are a model of epilepsy and depression co-morbidity that can be used for investigating underlying neurobiological and genetic mechanisms and screening novel therapeutics.

Purity of synthetic cannabinoids sold online for recreational use

The recreational use of synthetic cannabinoids has recently increased. This increase is due, in part, to the recent availability of inexpensive compound sold legally online in bulk. In particular, JWH-018 (1-pentyl-3-(1-naphthoyl)indole) and JWH-073 (1-butyl-3-(1-naphthoyl)indole) have been found in herbal blends marketed as alternatives to cannabis. Although these particular compounds have recently been emergency scheduled in the United States, online suppliers have shifted sales to other, similar compounds that are not currently scheduled. However, the purity of the drugs obtained from online suppliers is not known. Relative purity of JWH-018 and JWH-073 from three different online suppliers was determined using high-performance liquid chromatography with ultraviolet detection and validated standards obtained from a traditional research chemical supplier. Our results show that JWH-018 and JWH-073 obtained from online vendors was of comparable purity to validated standards, even though the physical properties varied in color, texture, and odor. It is concluded that adverse events following consumption of synthetic cannabinoid preparations is unlikely to be due to impurities or residue from the manufacturing process, but rather to effects of the active drug or interactions with other psychoactive chemicals from herbs blended into products marketed as cannabis alternatives.

Lifelong rapamycin administration ameliorates age-dependent cognitive deficits by reducing IL-1β and enhancing NMDA signaling

Understanding the factors that contribute to age-related cognitive decline is imperative, particularly as age is the major risk factor for several neurodegenerative disorders. Levels of several cytokines increase in the brain during aging, including IL-1β, whose levels positively correlate with cognitive deficits. Previous reports show that reducing the activity of the mammalian target of rapamycin (mTOR) extends lifespan in yeast, nematodes, Drosophila, and mice. It remains to be established, however, whether extending lifespan with rapamycin is accompanied by an improvement in cognitive function. In this study, we show that 18-month-old mice treated with rapamycin starting at 2 months of age perform significantly better on a task measuring spatial learning and memory compared to age-matched mice on the control diet. In contrast, rapamycin does not improve cognition when given to 15-month-old mice with pre-existing, age-dependent learning and memory deficits. We further show that the rapamycin-mediated improvement in learning and memory is associated with a decrease in IL-1β levels and an increase in NMDA signaling. This is the first evidence to show that a small molecule known to increase lifespan also ameliorates age-dependent learning and memory deficits.

Pharmacologic characterization of a nicotine-discriminative stimulus in rhesus monkeys

This study examined mechanisms by which nicotine (1.78 mg/kg base s.c.) produces discriminative stimulus effects in rhesus monkeys. In addition to nicotine, various test compounds were studied including other nicotinic acetylcholine receptor agonists (varenicline and cytisine), antagonists [mecamylamine and the α4β2 receptor-selective antagonist dihydro-β-erythroidine (DHβE)], a nicotinic acetylcholine receptor antagonist/indirect-acting catecholamine agonist (bupropion), and non-nicotinics (cocaine and midazolam). Nicotine, varenicline, and cytisine dose-dependently increased drug-lever responding; the ED(50) values were 0.47, 0.53, and 39 mg/kg, respectively. Bupropion and cocaine produced 100% nicotine-lever responding in a subset of monkeys, whereas mecamylamine, DHβE, and midazolam produced predominantly vehicle-lever responding. The training dose of nicotine resulted in 1128 ng/ml cotinine in saliva. Mecamylamine antagonized the discriminative stimulus effects of nicotine and varenicline, whereas DHβE was much less effective. Nicotine and varenicline had synergistic discriminative stimulus effects. In monkeys responding predominantly on the vehicle lever after a test compound (bupropion, cocaine, and midazolam), that test compound blocked the nicotine-discriminative stimulus, perhaps reflecting a perceptual-masking phenomenon. These results show that nicotine, varenicline, and cytisine produce discriminative stimulus effects through mecamylamine-sensitive receptors (i.e., nicotinic acetylcholine) in primates, whereas the involvement of DHβE-sensitive receptors (i.e., α4β2) is unclear. The current nicotine-discrimination assay did not detect a difference in agonist efficacy between nicotine, varenicline, and cytisine, but did show evidence of involvement of dopamine. The control that nicotine has over choice behavior can be disrupted by non-nicotinic compounds, suggesting that non-nicotinics could be exploited to decrease the control that tobacco has over behavior.

Morphine-induced motor stimulation, motor incoordination, and hypothermia in adolescent and adult mice

RATIONALE

Given evidence for age-related differences in the effects of drugs of abuse, surprisingly few preclinical studies have explored effects of opioids in adolescents (versus adults).

OBJECTIVES

This study compared the motor stimulating, ataxic, and hypothermic effects of morphine in adolescent, late adolescent, and adult mice. Plasma and brain levels of morphine were assessed to examine possible pharmacokinetic differences among the age groups.

METHODS

Locomotion was measured as occlusions of horizontal infrared light beams, ataxia as failing the horizontal wire test, body temperature by rectal probe, and morphine levels by HPLC-UV.

RESULTS

Morphine (3.2-56 mg/kg, i.p.) increased locomotion along an inverted U-shaped dose-response curve in adolescent, late adolescent, and adult male C57BL/6J mice. Its potency to stimulate locomotion was similar in all age groups. However, maximal stimulation was higher in adolescents than in late adolescents, and higher in late adolescents than in adults. In contrast, adolescents showed less ataxia than adults when given morphine (5.6-100 mg/kg, i.p.). The hypothermic effects of morphine did not differ among the age groups. Morphine levels, which peaked in plasma at 15 min and in brain at 45 min after i.p. injection, did not show age-related differences.

CONCLUSIONS

The finding that adolescents are not generally more sensitive to morphine than adults, but differ in their sensitivity to effects involving nigrostriatal/mesolimbic dopamine systems, is consistent with evidence of overactivity of these dopamine systems during adolescence relative to adulthood. The age-related differences observed here are unlikely due to pharmacokinetic factors.

Serum NPY and BNDF response to a behavioral stressor in alcohol-dependent and healthy control participants

RATIONALE

Neuropeptide Y (NPY) and brain-derived neurotrophic factor (BDNF) have been implicated in both the stress response and alcohol addiction. However, few studies have assessed the NPY and BDNF response to stress in alcohol-dependent participants and the concurrent measure of NPY and BDNF has not been reported in human participants.

OBJECTIVE

The purpose of this study was to concurrently assess serum NPY and BDNF, as well as adrenocorticotropin (ACTH) and cortisol, in control and race- and aged-matched abstinent alcohol-dependent participants in response to a stress-inducing public-speaking task.

METHODS

Basal and post-stress serum values of NPY and BDNF, as well as ACTH and cortisol, were assessed in 14 abstinent alcohol-dependent and ten healthy control male participants.

RESULTS

Basal measures were stable over short periods of time and stress induced a significant increase in both NPY (p = 0.002) and BDNF (p = 0.006) as well as ACTH (p < 0.001) and cortisol (p < 0.007). Alcohol-dependent and control groups did not significantly differ on any basal or stress-induced measure. Basal and delta responses of NPY and BDNF were not significantly correlated, and delta peak responses of NPY and BDNF did not correlate with one another or with their respective ACTH and cortisol responses.

CONCLUSIONS

These findings reveal that both serum NPY and BDNF are responsive to behavioral stressors, although their regulatory mechanisms appear to differ from one another and those of the hypothalamic-pituitary-adrenal axis. Differences in basal and stress-induced responses of NPY and BDNF were not supported between control and abstinent alcohol-dependent subjects.

Pharmacogenetic approach at the serotonin transporter gene as a method of reducing the severity of alcohol drinking

OBJECTIVE

Severe drinking can cause serious morbidity and death. Because the serotonin transporter (5-HTT) is an important regulator of neuronal 5-HT function, allelic differences at that gene may modulate the severity of alcohol consumption and predict therapeutic response to the 5-HT(3) receptor antagonist, ondansetron.

METHOD

The authors randomized 283 alcoholics by genotype in the 5'-regulatory region of the 5-HTT gene (LL/LS/SS), with additional genotyping for another functional single-nucleotide polymorphism (T/G), rs1042173, in the 3'-untranslated region, in a double-blind controlled trial. Participants received either ondansetron (4 μg/kg twice daily) or placebo for 11 weeks, plus standardized cognitive-behavioral therapy.

RESULTS

Individuals with the LL genotype who received ondansetron had a lower mean number of drinks per drinking day (-1.62) and a higher percentage of days abstinent (11.27%) than those who received placebo. Among ondansetron recipients, the number of drinks per drinking day was lower (-1.53) and the percentage of days abstinent higher (9.73%) in LL compared with LS/SS individuals. LL individuals in the ondansetron group also had a lower number of drinks per drinking day (-1.45) and a higher percentage of days abstinent (9.65%) than all other genotype and treatment groups combined. For both number of drinks per drinking day and percentage of days abstinent, 5'-HTTLPR and rs1042173 variants interacted significantly. LL/TT individuals in the ondansetron group had a lower number of drinks per drinking day (-2.63) and a higher percentage of days abstinent (16.99%) than all other genotype and treatment groups combined.

CONCLUSIONS

The authors propose a new pharmacogenetic approach using ondansetron to treat severe drinking and improve abstinence in alcoholics.

Sequential combination of self-report, breath carbon monoxide, and saliva cotinine to assess smoking status

The purpose of this analysis was to develop an algorithm for the cost effective and accurate assessment of smoking during the previous few days by combining self-report, breath carbon monoxide (BCO), and saliva cotinine (sCOT). These measurements are convenient, quantitative, and do not require invasive procedures. The data used to devise the algorithm were gathered during a treatment trial of participants seeking to stop smoking. Self-report of smoking was determined using a written questionnaire, BCO was measured with a handheld breathalyzer, and sCOT was quantified using a high sensitivity ELISA. Participants were 130 males and 97 females between the ages of 19 and 67 years who reported smoking at least 15 cigarettes a day and had a BCO level ≥ 15 ppm. Self-reports and BCO levels were collected at each of 6 visits (V0-V5) and sCOT levels were determined at V0 and V5. Based on the data collected, we recommend that the sequential determination of self-reported smoking, BCO level, and sCOT level be employed to assess smoking during the previous few days to minimize the higher cost and longer turnaround time associated with the sCOT test while maximizing accuracy.

Dehydration increases sodium-dependent glutamate uptake by hypothalamic paraventricular nucleus synaptosomes

OBJECTIVES

The purpose of this study was to identify and characterize Na+-dependent, high affinity glutamate transporter (GLUT) activity in the hypothalamic paraventricular nucleus (PVN) and to compare GLUT activity in PVN of euhydrated versus water-deprived rats.

METHODS

Sprague-Dawley rats were deprived of water for two days before sacrifice. Control rats received water ad libitum. After sacrifice, PVN and cerebrum were removed and synaptosomes were prepared using standard techniques. Glutamate uptake was measured using [3H]-glutamate as substrate, physiological buffer, approximately 100 µg of synaptosomal tissue per assay and a Brandel cell harvester.

RESULTS

Glutamate uptake was saturable in PVN synaptosomes from euhydrated, control rats with a Vmax of 541 ± 22 pmol/min-mg protein (SEM) and Km of 17.6 ± 3.8 µM (SEM). In contrast, Vmax of glutamate uptake was 808 ± 58 pmol/min-mg protein in PVN of rats deprived of water for 2 days. This was significantly higher than controls (p<0.001). Km was 21.2 ± 7.3 µM and not significantly different from controls (NS).

CONCLUSIONS

Our results suggest that water deprivation of rats results in significantly higher synaptosomal glutamate uptake in PVN. Although the exact mechanism is unknown, increased transcription of the GLUT gene and/or increased cell surface expression of GLUT may contribute to the observed increase of glutamate uptake in dehydrated rats. Increased glutamate uptake may serve to restrict dehydration-induced activation of PVN efferent pathways specifically involved in release of neurohypophysial hormones and activation of sympathetic outflow that operate to maintain body fluid balance and cardiovascular function.

Rapamycin, but not resveratrol or simvastatin, extends life span of genetically heterogeneous mice

Rapamycin was administered in food to genetically heterogeneous mice from the age of 9 months and produced significant increases in life span, including maximum life span, at each of three test sites. Median survival was extended by an average of 10% in males and 18% in females. Rapamycin attenuated age-associated decline in spontaneous activity in males but not in females. Causes of death were similar in control and rapamycin-treated mice. Resveratrol (at 300 and 1200 ppm food) and simvastatin (12 and 120 ppm) did not have significant effects on survival in male or female mice. Further evaluation of rapamycin's effects on mice is likely to help delineate the role of the mammalian target of rapamycin complexes in the regulation of aging rate and age-dependent diseases and may help to guide a search for drugs that retard some or all of the diseases of aging.